OBJECTIVETo explore the effect of Ginkgo biloba extract (GBE) on the function of alveolar polymorphonuclear neutrophils (PMN) in severe acute pancreatitis (SAP) rats complicated with lung injury (LI).

METHODSForty-eight adult SD rats were randomly divided into three groups, i.e., the sham-operation group, the SAP group, and the GBE treatment group, 16 in each group. The SAP model was successfully induced by retrograde injection of 5% sodium taurocholate solution into the biliopancreatic duct. Rats in the sham-operation group only received flipping of the duodenum. Those in the GBE treatment group received GBE intervention based on SAP model. Equal volume of normal saline was given to rats in the sham-operation group and the SAP group. Rats were sacrificed at 6 and 12 h after operation respectively. The lung tissue was sampled to evaluate the LI score. The wet/dry ratio (W/D) of lung tissues was detected. The activity of myeloperoxidase (MPO) was measured. Alveolar PMN was harvested by bronchoalveolar lavage. The content of neutrophil elastase (NE) in bronchoalveolar lavage fluid (BALF) was measured by enzyme-linked immunoabsorbent assay (ELISA). The percentage of CD11b/CD18 double positive PMN was detected using flow cytometry. The expression of intercellular adhesion molecule-1 (ICAM-1) and NE protein in the lung tissue was detected by Western blot.

RESULTSCompared with the sham-operation group, significant pathologic lesion occurred in the lung tissue of rats in the SAP group; the pathologic LI score, lung tissue W/D ratio, MPO, and NE content in BALF significantly increased, the expression of ICAM-1 and NE in the lung tissue was obviously up-regulated, and the percentage of CD11b/CD18 double positive PMN significantly increased (P < 0.01). Compared with the SAP group, pathological lesion of the lung tissue was obviously attenuated, and the above indices were all significantly declined in the GBE treatment group (P < 0.01).

CONCLUSIONSExpression of ICAM-1 in the lung tissue and the percentage of D11b/ CD18 double positive PMN were up-regulated in SAP rats complicated with LI, resulting in the adherence of PMN to pulmonary vascular endothelial cells, and then activating PMN to release NE and aggravate LI. GBE could alleviate LI through down-regulating the expression ICAM-1 and CD11b/CD18, and hindering the adherence and activation of PMN to pulmonary vascular endothelial cells.